Passing Argument to lm in R within Function

Question

I would like to able to call lm within a function and specify the weights variable as an argument passed to the outside function that is then passed to lm. Below is a reproducible example where the call works if it is made to lm outside of a function, but produces the error message Error in eval(expr, envir, enclos) : object 'weightvar' not found when called from within a wrapper function.

olswrapper <- function(form, weightvar, df){
  ols <- lm(formula(form), weights = weightvar, data = df)
  }

df <- mtcars

ols <- lm(mpg ~ cyl + qsec,  weights = gear, data = df)
summary(ols)

ols2 <- olswrapper(mpg ~ cyl + qsec,  weightvar = gear, df = df)
#Produces error: "Error in eval(expr, envir, enclos) : object 'weightvar' not found"

Answer 1

Building on the comments, gear isn't defined globally. It works inside the stand-alone lm call as you specify the data you are using, so lm knows to take gear from df.

Howver, gear itself doesn't exist outside that stand-alone lm function. This is shown by the output of gear

> gear
Error: object 'gear' not found

You can pass the gear into the function using df$gear

weightvar <- df$gear
ols <- olswrapper(mpg ~ cyl + qsec, weightvar , df = df)